chore: leverage fallback resolver for MSRV check

[gruebel]

Changes

This supersedes #2976 because I somehow was able to push the branch directly to the main repo. now it is from my fork 🙂

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.4%. Comparing base (4b3a383) to head (b803ee9).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2993   +/-   ##
=====================================
  Coverage   81.4%   81.4%           
=====================================
  Files        126     126           
  Lines      24573   24573           
=====================================
  Hits       20008   20008           
  Misses      4565    4565           

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[cijothomas]

Nice improvement! I was always worried about the need to constantly patch deps. Thanks for taking care of this.

[hdost]

@cijothomas @gruebel @lalitb
This fundamentally breaks MSRV checking. There is now no longer MSRV checking...
Related: open-telemetry/opentelemetry-rust-contrib#263